Morgan Michael Kerin, Rochford Andrew Michael, Tsahtsarlis Antonio, Little Nicholas, Faulder Kenneth Charles
Sydney Aneurysm and AVM Neurosurgical Centre, The University of Sydney, Royal North Shore Hospital, 193 Macquarie Street, Sydney, NSW 2000, Australia.
Neurosurgery. 2004 Apr;54(4):832-7; discussion 837-9. doi: 10.1227/01.neu.0000114264.78966.be.
Grade I and II arteriovenous malformations (AVMs) have been considered safe to resect. However, unoperated low-grade AVMs have not been considered in previously reported series. The aim of this study was to examine all cases, both operated and unoperated, to identify any characteristics of low-grade AVMs that comprise a subgroup that might pose a relatively higher risk.
A prospectively enrolled AVM database included 237 patients in Spetzler-Martin Grade I or II. These patients were analyzed on the basis of demographic characteristics, angiographic and magnetic resonance imaging features, clinical presentation, method of treatment, and outcome.
Surgery was performed in 220 patients in Spetzler-Martin Grade I or II. Seventeen patients did not undergo treatment because of poor neurological condition (six patients), patient refusal (nine patients), and perceived surgical difficulty (AVM size approaching 3 cm adjacent to Broca's area) (two patients). The overall surgical morbidity rate was 0.9%, and the mortality rate was 0.5%. Adverse outcomes occurred in 1 (0.6%) of 180 patients with AVMs located away from eloquent cortex and in 2 (5%) of 40 patients with AVMs adjacent to eloquent cortex. None of 28 surgical patients with deep venous drainage had an adverse outcome. All 219 patients who survived surgery underwent postoperative angiography that confirmed cure. No postoperative hemorrhage has occurred in 1143 patient-years of follow-up (mean follow-up, 5.3 yr).
When considering adverse outcome in the surgical series of Grade I and II AVMs alone, no statistical difference between non-eloquently located AVMs (0.6%) and eloquently located AVMs (5% adverse outcome) can be detected. However, consideration of all Grade I and II AVMs, both surgical and nonsurgical, may prove that a difference in outcome exists between these two groups masked by case selection. Generalization of the chances of adverse outcomes to all Grade I and II AVMs (both operated and unoperated) suggests that the risk of performing surgery on noneloquent brain in our series was 0.6% and that in eloquent brain could have been as high as 9.5%, had all such patients undergone surgery.
I级和II级动静脉畸形（AVM）被认为切除是安全的。然而，既往报道的系列研究中未考虑未经手术治疗的低级别AVM。本研究的目的是检查所有病例，包括已手术和未手术的，以确定低级别AVM中可能构成相对较高风险亚组的任何特征。
一个前瞻性登记的AVM数据库纳入了237例Spetzler-Martin I级或II级患者。根据人口统计学特征、血管造影和磁共振成像特征、临床表现、治疗方法及结果对这些患者进行分析。
220例Spetzler-Martin I级或II级患者接受了手术。17例患者因神经功能状态差（6例）、患者拒绝（9例）以及认为手术困难（AVM大小接近3 cm且毗邻Broca区）（2例）而未接受治疗。总体手术发病率为0.9%，死亡率为0.5%。位于非功能区皮质的180例AVM患者中有1例（0.6%）出现不良结局，位于功能区皮质附近的40例AVM患者中有2例（5%）出现不良结局。28例有深静脉引流的手术患者均未出现不良结局。所有219例术后存活的患者均接受了术后血管造影，证实病变已治愈。在1143患者年的随访中（平均随访5.3年）未发生术后出血。
仅考虑I级和II级AVM手术系列中的不良结局时，未发现位于非功能区的AVM（0.6%）和位于功能区的AVM（不良结局5%）之间存在统计学差异。然而，考虑所有I级和II级AVM，包括手术和非手术的，可能证明这两组之间存在结局差异，而这种差异被病例选择所掩盖。将所有I级和II级AVM（包括已手术和未手术的）不良结局的可能性进行归纳，表明在我们的系列研究中，对非功能区脑进行手术的风险为0.6%，而对功能区脑进行手术的风险如果所有此类患者都接受手术可能高达9.5%。
